Air outlet device for ventilating apparatus



July 20, 1954 F. J. KURTH ETAL 2,684,024

AIR OUTLET DEVICE FOR VENTILATING APPARATUS Filed May 25, 1951 e2 e4 23 1 16 v INVENTORS Fwmz Jm,

A ORNEY UNITED STATES Patented July 20, 1954 AIR OUTLET DEVICE FOR. VENTILATING APPARATUS Franz J. Kurth, Mamaroneek, N. Y., and Leonard R. Phillips, East Hartford, Conn, assignors to Anemostat Corporation of America, New York,

TENT OFFICE 3 Claims.

This invention relates to ventilating apparatus and has particular reference to improvements in outlet devices through which so-called supply air from a duct or other source of supply is delivered into rooms or other enclosures for ventilating, heating, cooling or other purposes.

More particularly, the present invention relates to air outlet devices of the type which are operable to effect recirculation of the air of a room or other enclosure into which they deliver air. In other words, the present invention relates to air outlet devices of the type which utilize supply air flowing therethrough to induce room or enclosure air into the devices and to mix the induced air with the supply air, usually in order to effect more or less temperature and humidity equalization between the supply air and the room or enclosure air prior to delivery of the supply air into the room or enclosure.

In many instances it may be desirable for one reason or another to recirculate more of the air of a room or enclosure than heretofore. Known air outlet devices of the type mentioned are of limited induction or recirculating capacity and therefore, in any such instance, to utilize a known outlet device of the type mentioned for the recirculation of more than the usual amount of the air of a room or other enclosure, would require an increase in the amount of the supply air, at increased operating cost. Moreover, it has been found that proper ventilation or air conditioning of a room or other enclosure does not require as many air changes per any given period of time, or, in other words, as much supply air, as has heretofore been considered necessary.

Accordingly, the primary object of the present invention is to provide an air outlet device embodying a simple, practical construction whereby it is effective, due to flow of any given amount of supply air through to same, to induce into the device an exceptionally large amount of the air of a room or other enclosure into which the device discharges and to mix the induced air with the supply air. Thus, in existing installations more than the usual amount of room or enclosure air may be recirculated without increasing the amount of the supply air or, in fact, by .actually reducing the amount of the supply air with consequent decrease in operating costs. On the other hand, in new installations duct sizes and fans may be smaller than in existing installations with consequent material savings in space, installation and operating costs.

Another object of the invention is to provide an air outlet device which additionally embodies a simple, practical construction whereby the mixed supply and room or enclosure air discharged therefrom is effectively diffused.

With the foregoing and other objects in view, the invention consists in an air outlet device embodying the novel features of construction, combination and arrangement of parts as are illustrated by way of examples in the accompanying drawing and as Will be hereinafter more fully described and claimed.

In the accompanying drawing, wherein like characters of reference denote corresponding parts in the different views:

Fig. l is a central, longitudinal section through an air outlet constructed in accordance with one practical embodiment of the invention and illustrated as being operatively mounted relative to an air supply duct, and

Fig. 2 is a transverse section on the line 2-2 of Fig. 1.

Referring to the drawing in detail, it will be observed that the present air outlet device, according to the specific embodiment thereof illustrated, is composed primarily of an outer, open-ended, hollow member iii and an inner member H which is disposed within and spaced from the member if! to provide between said members an air passageway a.

The outer member it includes a front, flaring portion [2 and a neck, designated generally as l3, which extends rearwardly from said front, flaring portion and which is of least diameter intermediate its ends as indicated at Hi.

From its portion id of least diameter the neck 53 flares forwardly, as indicated at l5, to its junction with the rear end of the front, flared portion i2, while rearwardly from its portion It said neck preferably but not necessarily, flares rearwardly, as indicated at it. As shown, the front, flared portion if has a materially greater amount of flare than the flared portion i5.

The inner member II has a portion ll of greatest diameter laterally alined with the portion M of least diameter of the neck l3 and from its said portion I! of greatest diameter is tapered forwardly, as indicated at It, and then is flared forwardly and outwardly as indicated at I9.

Rearwardly of its portion ll of greatest diameter the inner member ll may be of any suitable form, but preferably is tapered rearwardly as indicated at 20.

As is apparent, the members It and H cooperate to provide between them the air or gas passageway a which is constricted to provide a throat as indicated at a, between the portions is and I? of said members and which, between the portions l6 and 20 of said members, tapers or converges forwardly toward said throat so that said passageway is of Venturi form. In alinement with said constriction or throat, longitudinally of the device and between the portions 15 and I8 of said members, the passage-- way a flares forwardly a limited amount and then, between the flared portions l2 and [9 of said members, flares a greater amount forwardly and outwardly to provide for rapid release of pressure and corresponding acceleration of flow of air through the throat a.

The rear end of the neck l3 of the outer memher it) may be connected in any suitable manner with an air supply duct D, so that air is supplied to the rear end of the passageway a from said duct. Alternatively, air may be supplied to the rear end of the passageway a from any other source of supply or in any other suitable manner. In any event, due to the forward convergence or taper of the rear portion of the passageway a, to the constriction or throat a of said passageway between the portions l4 and I"! of the memhere It and I l and to the forwardly flaring form of said passageway forwardly of said constriction, air introduced into said passageway at any given velocity and flowing forwardly therethrough has its velocity accelerated in accordance with Bernoullis well known law.

As will be understood, the air outlet device is mounted to discharge at its front end into a room or other enclosureand may or may not have its neck l3 exposed within the enclosure.

As will also be understood, the device may be of circular shape, as shown, or of any other desired shape such as rectangular, semi-circular or the like in transverse section. Hence, the passageway a may be either endless or substantially endless or simply elongated in transverse section and, as a whole may be of any transverse sectional shape, depending upon the transverse sectional shape of the device.

In accordance with the invention, flow of the supply air through the device is utilized to effect induction of enclosure air into the device and mixing of the induced air with the supply air, thus to utilize part of the enclosure air to compensate in large measure for differences in temperature and humidity between the supply air and the enclosure air prior to flow of air from the device into the enclosure.

To provide for induction of enclosure air into the device due to flow of supply air through the passageway a, the inner member H may be hollow and open at its front and rear ends as shown. Thus, flow of supply air through the passageway a will have the effect of inducing enclosure air to flow rearwardly through said inner member H to the rear end of said inner member where it will be picked up and be drawn forwardly through the passageway a by the supplied air. In being picked up and drawn forwardly by the supply air the induced air will, of course, become mixed with the supplied air.

Between the flared portions [2 and [9 of the members Hi and I! may be disposed an openended, hollow, flaring member 2| or any suitable plurality of such members to divide the air flowing through the front portion of the passage" way a into a plurality of separate streams and to deflect said streams more or less laterally outwardly, thus to assist in diffusing the air. However, even in the absence of a member, or mem- 4 bers, such as the member 2|, the flared portion IQ of the member Ii will act to deflect the air laterally outward whereby any blast effect directly forwardly of the device is avoided and diffusion is enhanced.

If the inner member II is hollow and open at its ends, it is important to shield said member against iiow of supply air forwardly therethrough and to direct the supply air only into the passageway a. This may be done in any suitable manner as, for example, by locating a suitable shield element 22 behind and in spaced relationship to the rear end of said inner member H. In this connection and according to the example of the invention illustrated in the drawing, the shield element 22 is constituted by a portion of a wall 23 of the duct D against which the device is fastened. In said shield element 22 are openings 25 which are alined longitudinally of the device with the passageway a whereby air is delivered from said duct only into said passageway a.

Another manner of providing for induction of enclosure air into the device due to flow of supply air through the passageway a, is to form openings 25 in the rear portion IQ of the outer member ID. This is practicable if the neck l3 of the device is exposed within the enclosure into which the device discharges.

Still another manner of providing for induction of enclosure air into the device due to iiow of supply air through the passageway a, is to locate an open-ended tube '26 with one end thereof behind and spaced from the inner member H and with its other end suitably exposed to the enclosure air.

Obviously, any of the three described manners of providing for induction of enclosure air into the device may be used to the exclusion of the other two, or any two of them may be used to the exclusion of the other one, or all three may be used if desired. In fact, any equivalent of any of the illustrated and described means may be used in lieu of any of said means to provide for induction of enclosure air into the device. In this connection and as will be understood, the inner member H may be solid or, if hollow, may be closed at any suitable point against flow of air therethrough if it is not used for air induction purposes.

From the foregoing description considered in connection with the accompanying drawing it is believed that the construction and operation of the present air outlet device will be clearly understood and its advantages appreciated. It is desired to point out, however, that while only a single, specific structure embodiment of the invention has been illustrated and described, the same is readily capable of specifically different structural embodiments within its spirit and scope as defined in the appended claims.

We claim:

1. An air outlet for ventilating apparatus comprising an inner open-ended hollow member, an outer member spaced from and surrounding said inner member to provide between said members a passageway which extends longitudinally of the device and which is endless transversely of the device, said passageway being open at its rear end for supply of air thereto and being open at its front end for discharge of air therefrom into an enclosure, said members being of sectional shapes such that said passageway includes a constricted intermediate throat portion, a rear portion converging forwardly toward said throat portion, and a front portion flaring forwardly from said throat portion, whereby supply air entering the rear end of said passageway at any given velocity and flowing forwardly therethrough has its velocity accelerated, and a shield element disposed behind said inner member and having therein openings which are alined longitudinally of the device with said passageway and through which supply air is delivered to said passageway, the rear end of said inner member being spaced forwardly from said shield element to afford a space for induction of enclosure air rearwardly through said inner member and into said passageway by flow of supply air forwardly through said passageway.

2. An air outlet device for ventilating apparatus comprising outer and inner members spaced apart to provide between them a passageway extending longitudinally of the device, said passageway being open at its rear end for supply of air thereto and being open at its front end for discharge of air therefrom into an enclosure, said members being of sectional shapes such that said passageway includes a throat, a rear portion converging forwardly toward said throat and a front portion flaring forwardly from said throat, whereby supply air entering the rear portion of said passageway at any given velocity and flowing forwardly therethrough has its velocity accelerated, an element located rearwardly of said members and having therein openings for flow of supply air therethrough to said passageway, said openings being alined longitudinally of the device with said passageway whereby supply air is delivered only to said passageway, the rear end of one of said members being spaced forwardly from said element to provide communication exteriorly of said passageway between the ambient air and the space between said element and the rear end of said one of said members, whereby supply air flowing forwardly through said passageway induces ambient air into said passageway for admixture with the supply air.

3. An air outlet device for ventilating apparatus comprising outer and inner members spaced apart to provide between them a passageway extending longitudinally of the device, said passageway being open at its rear end for supply of air thereto and being open at its front end for discharge of air therefrom into an enclosure, said members being of sectional shapes such that said passageway includes a throat, a rear portion converging forwardly toward said throat and a front portion flaring forwardly from said throat, whereby supply air entering the rear portion of said passageway at any given velocity and flowing forwardly therethrough has its velocity accelerated, said inner member being hollow and open at its ends and affording communication between the ambient air and said passageway, and means to prevent supply air from flowing into said inner member and to cause it to flow only through said passageway whereby it is caused to induce flow of enclosure air through said inner member into said passageway for admixture with the supply air.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,142,134 Kurth Jan. 3, 1939 2,189,008 Kurth Feb. 6, 1940 2,209,121 Honerkamp July 23, 1940 2,418,266 Kurth et a1. Apr. 1, 1947 2,519,503 Rigaumont Aug. 22, 1950 FOREIGN PATENTS Number Country Date 341,460 Great Britain Jan. 16, 1931 

